Just to be clear, I'm going to have an insulator board, so no screws/nuts will be going under that. I'm building the eyelet board and insulator board out of 1/16" Garolite XX (left over from my Bassman build). The Garolite is not as flexible as the vulcanized fiberboard material from Mojotone. I think its flexural strength is fairly good. However, just to be safe, I don't want to put much stress on it torquing the screws down with all the wires and jumpers underneath. So, I'll be putting some 1/8" tall standoffs in between the boards. The boards will be be the same width and length as the Mojotone PR boards. It'll be 2.375" wide, which is slightly narrower than the 2.5" originals. I think Mojotone did that because on the originals, Fender mounted the OT with self tapping screws. That left enough room for the board to sit in between those screws. There wouldn't be enough clearance with hex nuts there.